<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
			body {
				position: relative;
				background: linear-gradient(to right top, #409eff 50%, #0003 50%);
				background-size: 100% calc(100% - 100vh + 5px);
				background-repeat: no-repeat;
				z-index: 1;
			}
			/* 使用固定定位控制位置 */
			body::after {
				content: "";
				position: fixed;
				top: 5px;
				left: 0;
				right: 0;
				bottom: 0;
				background-color: #fff;
				z-index: -1;
			}
			div {
				height: 99999px;
			}
		</style>
	</head>
	<body>
		<div></div>
	</body>
</html>